咸池沟弃渣场渣体大型三轴试验研究

结合咸池沟弃渣场地质条件与现场工况,通过饱和试样大型三轴试验,分析了渣体材料在不同围压下应力—应变关系特性、变形特性以及抗剪强度特性。试验结果表明：该渣体材料不同于一般堆石料,其在轴向压力作用下无明显应变软化特性;随围压增大,渣体由剪胀逐渐过渡到剪缩,且在低围压下,渣体剪胀性在不同应力水平时表现不同;围压较低时,经典线性摩尔—库伦模型仍然适用于该渣体强度分析,但设计数据偏于保守;在高围压下应建立非线性强度模型。在试验分析和理论研究的基础上,认为有必要开展应力路径与应力历史对渣体材料力学特性影响的研究,为依托工程的设计及后期防护奠定理论基础。

Large-scale triaxial test study on behaviors of discarded soil field in Xianchi gully

Based on the geological conditions and working conditions on the discarded soil field in Xianchi gully, the stress-strain relationship, the deformation feature and the shear strength behavior of the discarded soil under different confining pressures are analyzed through the large-scale triaxial tests. The test results indicate that the discarded soil is different from other rockfill materials. The material is characterized by no strain softening under axial pressure. The samples vary from the dilation to volume shrink with the increasing of the confining pressures. The characteristics of the shear dilation are different in different stress level under low confining pressures. The classical linear Moore-Coulomb model can still be applied to the strength analysis of the discarded soil under low confining pressures and the design parameters are conservative, but the nonlinear strength model should be established under high confining pressures. Based on the test analysis and theoretical study, it is necessary to study the influence of stress path and stress history on the discarded soil, which will provide the theoretical base for the engineering design and the later-stage management.